Sn-Pb mixed perovskites with narrow bandgap (NBG) are important for high-performance single- and multi-junction perovskite solar cells (PSCs). However, the inherent Sn oxidation and ion migration lead to inferior stability. Herein, 2-hydrazino-2-imidazoline hydrobromide (2H2I) is employed as a coordinating additive to regulate the film crystallization and inhibit Sn oxidation. Meanwhile, 2H2I can form hydrogen bonds with I ions to suppress ion migration, thereby improving photovoltaic stability. The target FACsSnPbI:2H2I PSC exhibits a champion power conversion efficiency (PCE) of 22.44 %, higher than that of the control device (19.16 %). The target devices retain 90 % () and 80 % () of the initial PCE under maximum power point (MPP) tracking for 1360 h at room temperature and for 436 h at 65 °C, respectively, the highest values for NBG Sn-Pb PSCs. This work demonstrates an effective strategy toward photothermally stable Sn-Pb PSCs.

中文翻译：

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咪唑啉衍生物调制的具有高运行稳定性的窄带隙锡铅钙钛矿太阳能电池


窄带隙（NBG）锡铅混合钙钛矿对于高性能单结和多结钙钛矿太阳能电池（PSC）非常重要。然而，固有的Sn氧化和离子迁移导致稳定性较差。本文采用2-肼基-2-咪唑啉氢溴酸盐(2H2I)作为配位添加剂来调节薄膜结晶并抑制Sn氧化。同时，2H2I可以与I离子形成氢键，抑制离子迁移，从而提高光伏稳定性。目标 FACsSnPbI:2H2I PSC 的冠军功率转换效率 (PCE) 为 22.44%，高于控制器件 (19.16%)。在室温下 1360 小时和 65°C 下 436 小时的最大功率点 (MPP) 跟踪下，目标器件分别保留了初始 PCE 的 90% () 和 80% ()，这是 NBG Sn-Pb 的最高值PSC。这项工作展示了一种光热稳定 Sn-Pb PSC 的有效策略。